Re: [PATCH] hw/sd/sdhci: Do not force sdhci_mmio_*_ops onto all SD controllers

[Bernhard Beschow]

Am 16. Juli 2023 19:53:37 UTC schrieb Bernhard Beschow <shentey@gmail.com>:
>
>
>Am 10. Juli 2023 16:01:46 UTC schrieb Bernhard Beschow <shentey@gmail.com>:
>>
>>
>>Am 10. Juli 2023 10:16:35 UTC schrieb "Philippe Mathieu-Daudé" 
>><philmd@linaro.org>:
>>>On 9/7/23 10:09, Bernhard Beschow wrote:
>>>> Since commit c0a55a0c9da2 "hw/sd/sdhci: Support big endian SD host 
>>>> controller
>>>> interfaces" sdhci_common_realize() forces all SD card controllers to use 
>>>> either
>>>> sdhci_mmio_le_ops or sdhci_mmio_be_ops, depending on the "endianness" 
>>>> property.
>>>> However, there are device models which use different MMIO ops: 
>>>> TYPE_IMX_USDHC
>>>> uses usdhc_mmio_ops and TYPE_S3C_SDHCI uses sdhci_s3c_mmio_ops.
>>>> 
>>>> Forcing sdhci_mmio_le_ops breaks SD card handling on the "sabrelite" 
>>>> board, for
>>>> example. Fix this by defaulting the io_ops to little endian and switch to 
>>>> big
>>>> endian in sdhci_common_realize() only if there is a matchig big endian 
>>>> variant
>>>> available.
>>>> 
>>>> Fixes: c0a55a0c9da2 ("hw/sd/sdhci: Support big endian SD host controller
>>>> interfaces")
>>>> 
>>>> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
>>>> ---
>>>>   hw/sd/sdhci.c | 8 +++++++-
>>>>   1 file changed, 7 insertions(+), 1 deletion(-)
>>>> 
>>>> diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
>>>> index 6811f0f1a8..362c2c86aa 100644
>>>> --- a/hw/sd/sdhci.c
>>>> +++ b/hw/sd/sdhci.c
>>>> @@ -1382,6 +1382,8 @@ void sdhci_initfn(SDHCIState *s)
>>>>         s->insert_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, 
>>>> sdhci_raise_insertion_irq, s);
>>>>       s->transfer_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, 
>>>> sdhci_data_transfer, s);
>>>> +
>>>> +    s->io_ops = &sdhci_mmio_le_ops;
>>>>   }
>>>>     void sdhci_uninitfn(SDHCIState *s)
>>>> @@ -1399,9 +1401,13 @@ void sdhci_common_realize(SDHCIState *s, Error 
>>>> **errp)
>>>>   
>>>
>>>What about simply keeping the same code guarded with 'if (!s->io_ops)'?
>>
>>I chose below approach since it provides an error message when one attempts 
>>to set one of the other device models to BE rather than just silently 
>>ignoring it.
>>
>>Also, I didn't want to make the assumption that `s->io_ops == NULL` implied 
>>that sdhci_mmio_*_ops is needed. That's similar material the bug fixed is 
>>made of, so I wanted to prevent that in the first place by being more 
>>explicit.
>>
>>In combination with the new error message the limitations of the current code 
>>become hopefully very apparent now, and at the same time should provide 
>>enough hints for adding BE support to the other device models if ever needed.
>>
>>Best regards,
>>Bernhard
>
>Ping

Ping^2

I would like to have the bug fixed in 8.1.

Best regards,
Bernhard

>
>+ qemu--stable
>
>>
>>>
>>>>       switch (s->endianness) {
>>>>       case DEVICE_LITTLE_ENDIAN:
>>>> -        s->io_ops = &sdhci_mmio_le_ops;
>>>> +        /* s->io_ops is little endian by default */
>>>>           break;
>>>>       case DEVICE_BIG_ENDIAN:
>>>> +        if (s->io_ops != &sdhci_mmio_le_ops) {
>>>> +            error_setg(errp, "SD controller doesn't support big 
>>>> endianness");
>>>> +            return;
>>>> +        }
>>>>           s->io_ops = &sdhci_mmio_be_ops;
>>>>           break;
>>>>       default:
>>>